Spandex

Ah, thanks. Got it now from the Stribe firmware.

You're very kind, but really I'm more "busy" than "patient" :)

I'm still unable to get in via SVN. Is there somewhere else I can DL this source code? Failing that, is there any chance anyone with SSH+SVN access could zip me up a copy of recent export so that I can start looking at this MAX7221 driver? Please PM me if so. Thanks!

That's not how most firewalls work. OUTBOUND connections are allowed by default anyway. You can't predict the local port so you can't make holes for a particular protocol, nor do you need them. You're talking about INBOUND connections, I believe, or else some other flavour of restrictive firewall that prevents net access to your local users. We don't have anything like that (I know because I'm the network admin here :)) See below, I can connect on port 22 (though I have no account) but can't connect via SVN protocol. matt.southall@s15286839:~/tmp$ svn checkout svn://svnmios.midibox.org/mios/playground svn: Can't connect to host 'svnmios.midibox.org': Connection refused matt.southall@s15286839:~/tmp$ telnet svnmios.midibox.org 22 Trying 72.232.76.22... Connected to svnmios.midibox.org. Escape character is '^]'. SSH-1.99-OpenSSH_3.9p1 Protocol mismatch. Connection closed by foreign host. matt.southall@s15286839:~/tmp$ matt.southall@s15286839:~/tmp$ telnet svnmios.midibox.org 3690 Trying 72.232.76.22... telnet: Unable to connect to remote host: Connection refused matt.southall@s15286839:~/tmp$

Sorry, I've always setup svn over WebDAV/DeltaV before so I don't know much about the svn:// protocol. As far as I can see though, it shouldn't need any special firewall rules. It doesn't do anything crazy like initiate connections back to the originator like FTP does it? Also, if you have authenticated read/write access, you're possibly tunnelling it over SSH anyway?

I can't get it via svn:// protocol either. Tried under Debian (command line svn client) and Windows (Tortoise) from two different locations. TortoiseSVN is giving me: Error: Can't connect to host 'svnmios.midibox.org': No connection could be made because the target machine actively refused it. I tried svn://svnmios.midibox.org/mios/playground svn://svnmios.midibox.org/mios/ svn://svnmios.midibox.org/ and svn://svnmios.midibox.org/trunk/modules/max72xx/

After a long patch of "Real Life" happening to me, I'm about to get back into this.. but the SVN link seems to be broken. Has it moved in the meantime?

That's great! Looking at this code, it seems the only thing to add for the TLC5940 is PWM. i.e. the actual PWM clock (GCLK) and also a BLANK signal which marks the end of each duty cycle.

Good point about the DOUT + LED Driver. Hadn't occurred to me. I'll start looking at SID (or maybe MF) as places to hook it then. Will do. I'll definitely write it up... we're actually building three units so I need to do this for my own sanity too :)

I'm still waiting on my MIDIBox kit but a friend has posted me his (already built) so I'm going to start making the TLC5940s work with MIDIBox when that arrives. Can I ask where people would suggest I start? e.g. which pins might be best? Should I replace the DOUT driver with one for the TLC5940 instead? (we won't be using DOUT but we will be using DIN with rotary encoders). The minimum number of pins needed to drive the TLC5940 is 5... of which 3 are clock type signals (SCLK, GSCLK, BLANK), with GSCLK in particular being nice and fast as it's the PWM clock. I'd like to use at least 6bits of the PWM so a GSCLK speed of 6.4KHz or above would be good. The faster the better I guess. I still have to shift 192 bits in for each update (actually 960 as I'm chaining 5 chips) and I'd like to update them every 20 ms or faster. This list modified from http://www.arduino.cc/playground/Learning/TLC5940 .. a nice summary of the relevant datasheet stuff # XLAT: to latch data after shifting. # SCLK: clock for the serial in # SIN: serial in to TLC5940 # GSCLK: clock for the PWM. # BLANK: this marks the end of a PWM cycle in addition to blanking the output. And there's some nice commented arduino code here https://whatever.metalab.at/user/wizard23/tlc5940/arduino/TLC5940/ Which I've got working fine on a breadboard... if only the arduino had decent USB communication with low latency :) If anyone could give me a pointer as to where I should start looking, I'd be grateful. e.g. I'd be sad if I spent a week trying to plug it in where the DOUT module used to be, only to discover that it would have been loads easier to use the MotorFader stuff. Also, iI'm interested to know if your immediate thought is "that sounds ok in C" or "I'd use ASM to get the performance". I'm happier with C but I've done a little ASM before so I'm prepared to get my hands dirty. I hope my questions are getting smarter, if not shorter :) Thanks once again for allowing me to prevail upon your combined brainpower.

There's some good beginner stuff and example code for interfacing this chip (TLC5940) to Arduino here: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1204292903/6 http://www.arduino.cc/playground/Learning/TLC5940 This (along with the datasheet, obviously) should help in interfacing it to midibox. There are several packages and the DIP variant seems to be the TLC5940NT.

I see your point entirely, if you answered every query in this depth it'd be a full time job! Big thanks. I've ordered a few TLC5940s and I'll start trying to connect stuff soon (have only just ordered my MidiBox Core too).

That looks perfect. Thanks.

I'm appreciating this point more and more. Anybody have any recommendations over the PCA9635? I'm pretty new to soldering and would prefer not to have to deal with SMD. The maxim7219 seems to support dimming of ALL connected LEDs. I'm looking for an IC that will do them individually. I found an ST2226a which seems to be exactly what I want, but, like TK says, I can't actually buy the thing anywhere :/

Heheh.. yes :) Sorry.

Hmmm... well something isn't matching up here because I *did* search and read a *lot*. Before I posted, I considered all sorts of solutions. I'd found and read Ralf Suckow's page, I'd considered using Arduino instead etc... but there are several posts in these forums that talk about driving PWM LED matrixes using standard DOUT on MIDIBox, so I thought this might be the way to go. e.g. http://www.midibox.org/forum/index.php/topic,8224.0.html http://www.midibox.org/forum/index.php/topic,9711.0.html You probably read those threads and (because you know all this stuff inside out, and you know who's who) you know which posts to pay most attention to. For me, I just see a load of posts with some people saying "yeah that should be possible" and other people saying "no you can't". Imagine you're new to all this for a moment! Anyway, rather than gripe about it, I thought I'd be proactive and I added it to the FAQ on the Wiki. Hope this is appropriate. It would have saved me a few hours if this had been there. http://www.midibox.org/dokuwiki/questions_and_answers#can_i_use_pwm_to_control_led_brightness So, my two options now are to maybe use an LED bar graph instead (much easier but takes up more panel space), or to start looking at adding dedicated LED driver ICs (e.g. PCA9635 or ST2226a).

Twice today? I reckon that makes this Question a Frequently Asked one :) I'd read that thread and found it useful but also confusing. Mostly it seems to suggest that I'd need hardware and software mods, although the last post seems to suggest just a software mod. All YOUR posts say it's not possible without overloading the core.. so I'm going to assume that's the correct answer. Thanks.

Hi. About to start building a MIDIBox64e (together with a monome in a single enclosure :)). Hoping somebody can answer some questions. I've hunted round the Wiki/Forums so I really hope I'm not asking RTFM questions. Like this thread, I see lots of references to PWM LED control with DOUT but not much concrete anywhere. I'd like to use a single LED for each rotary encoder, using brightness to represent position. Will probably have 24 encoders. As I understand it, there's no simple builtin PWM in MIOS. So my questions are: 1) Can I do this for 24 LEDs using just DOUT boards? 2) If so, what sort of refresh rate would I get? 3) Does MIOS support this in any way or would I have to write some additional software? I'm comfortable with the software bit (have done PWM for servo control in Motorola 68k ASM before) but scared of departing from the standard DOUT kit because I'm no electronics expert. Ideally, I'd like to be able to have 24 LEDS with at least 128 diff brightnesses and no flicker. Am I going to struggle? Why has this chap made a hardware mod to drive the LEDs? Is it just about supplying them with more current for brightness? I couldn't see anything that looked like dedicated PWM in his hardware schematic or the software changes. My next question is probably going to be "What about 48 or 72 LEDS for bicolor or RGB" :) Any help greatly appreciated.